Siemens Aktiengesellschaft

Primetals Technologies Germany Gmbh

Klaus Franz

Klaus Weinzierl

Matthias Kurz

Stefan Schmors

Wolfgang Borchers

The invention relates to a method for controlling and/or regulating an industrial process for producing or processing products, wherein a physicomathematical model of the industrial process is formed, with which control parameters for controlling or regulating the industrial process are calculated during the production or processing of the product, a number of measurement values is detected, and the model is corrected with a number of primary correction factors, the number of primary correction factors being equal to the number of measurement values. The method is characterized in that the model is corrected with a number of secondary correction factors, such as with a correction factor reflecting the speed of the phase conversion in the rolling mill to be cooled, and in that the number of all correction factors is greater than the number of all measurement values, wherein at least the secondary correction factors are calculated numerically.

Method for controlling and/or regulating an industrial process

A steel volume is modeled in a computer by means of a plurality of volume elements. The state of the steel volume at a given time comprises, for each volume element, characteristic quantities of an enthalpy existing at said time in the respective volume element and percentages, in which the steel is available in the respective volume element at the time in austenite, ferrite and cementite phases. For at least one volume element, the computer determines the time gradient of the characteristic quantities by resolving thermal conductivity and phase transition equations. One of the characteristic quantities is a locally invariable mean interstitial element concentration within the volume element in the austenite phase thereof.

Method of modeling the time gradient of the state of a steel volume by means of a computer and corresponding objects

A computer determines a subsequent state of a steel volume, based on an instantaneous initial state of said steel volume and at least one volumetric surface, the temporary influence quantities acting on said steel volume, by resolution of an equation of thermal condition and phase change. The states include for at least one volumetric element of the steel volume, a local distribution in concentration of a alloy element mobile in the steel, the local proportions of the modeled phases of the steel and a quantity describing a local energy content of the steel. The phases include austenite and another phase, generally, ferrite or cementite. In the context of the change equation, the concentration levels of the mobile alloy element, which are located on either side of the phase boundary, between the austenite and the other phase are determined by resolution of a Stephan problem.

Computer-assisted modelling method for the behavior of a steel volume having a volumetric surface

The temperature (T) of a metal () can be influenced directly or indirectly by at least one actuator () which is actuated in accordance with a control variable (S). The control variable (S) and starting values (T, p, p) for a temperature of the metal () and phase proportions in which the metal () is at least in a first phase or a second phase, respectively, are predetermined for a material model (). A heat conduction equation and a transformation equation are solved in real time within the material model (), taking account of these variables (T, p, p) , and in this way expected values (T, p, p) are determined for these variables. As part of the transformation equation, the Gibbs' free energies (G, G) of the phases of the metal () are determined, a transformation rate of the metal () from the first phase to the second phase is determined therefrom, and the expected proportions (p, p) are determined from the latter.

Modeling method for a metal

To determine the temperature profile (Tm(t)) of a hot-rolled material () in a cooling line (), a heat conduction equation which takes the following formwhere e is the enthalpy, &#x3bb; the thermal conductivity, p the degree of phase transformation, &#x3c1; the density and T the temperature of the rolled material at the rolled-material location and t is the time, is solved in a cooling-line model ().

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Nürnberg, Germany

Klaus Franz